Organic compounds -- part of the class 532-570 series – Organic compounds – Four or more ring nitrogens in the bicyclo ring system
Patent
1992-08-25
1994-05-10
Bernhardt, Emily
Organic compounds -- part of the class 532-570 series
Organic compounds
Four or more ring nitrogens in the bicyclo ring system
564149, 564151, C07D23704
Patent
active
053107381
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a process for producing a hexahydropyridazine-1,2-dicarboxy derivative useful as an intermediate material for benzothiazine-type agricultural chemicals such as herbicides.
BACKGROUND ART
Heretofore, with respect to a hexahydropyridazine-1,2-dicarboxy derivative: ##STR2## a process has been proposed, for example, as disclosed in Arch. pharm. 295,526-32(1960), wherein diethylhydrazine dicarboxylate and dibromobutane are reacted in the presence of metal potassium using dimethylformamide as a solvent to obtain diethylhexahydropyridazine-1,2-dicarboxylate.
However, the above conventional process has a problem that metal potassium which is difficult to handle, is required to be used, and besides, the yield in the cyclization is as low as 16%.
The present invention has been accomplished for the purpose of solving the above-mentioned problem of the prior art and providing a process which is an industrial process and which is capable of producing a hexahydropyridazine-1,2-dicarboxy derivative in good yield.
DISCLOSURE OF THE INVENTION
To accomplish the above object, the present invention provides a process for producing a hexahydropyridazine-1,2-dicarboxy derivative represented by the general formula: ##STR3## (wherein R has the same meaning as R in the following general formula (1)), which comprises reacting a hydrazine dicarboxy derivative represented by the general formula: represented by the general formula: selected from an alkali metal carbonate or hydroxide.
Namely, the inventors of the present invention have found that the above mentioned hexahydropyridazine-1,2-dicarboxy derivative can be obtained in good yield by using a base selected from an alkali metal carbonate or hydroxide in the production of the hexahydropyridazine-1,2-dicarboxy derivative represented by the general formula (3) by reacting the hydrazine dicarboxy derivative represented by the general formula (1) with the dihalogenobutane represented by the general formula (2), and thus have accomplished the present invention.
Now, the present invention will be described in detail.
In this specification, for example, "the hydrazine dicarboxy derivative represented by the general formula (1)" will be represented by "the hydrazine dicarboxy derivative (1)".
The hydrazine dicarboxy derivative (1) to be used in the present invention, may be the one wherein substituent R in the formula is an alkoxy group or an aryl group. For example, dimethylhydrazine dicarboxylate, dipropyl hydrazine dicarboxylate, diethyl hydrazine dicarboxylate or dibenzoyl hydrazine may be used.
Further, the dihalogenobutane (2) may be the one wherein substituent X in the formula is a chlorine or bromine atom. For example, 1,4-dibromobutane, 1,4-dichlorobutane or 1-bromo-4-chloro-butane may be used.
Further, as the alkali metal carbonate or hydroxide, potassium carbonate, sodium carbonate, sodium hydroxide or potassium hydroxide may, for example, be used. Further, in the above reaction of the hydrazine dicarboxy derivative (1) with the dihalogenobutane (2), a solvent or water may be used to facilitate the stirring. As such a solvent, acetonitrile, benzene, toluene, xylene or dimethylformamide may, for example, be mentioned. In some cases, a phase transfer catalyst such as quaternary ammonium or quaternary phosphonium may be employed.
The ratio of the amounts of the hydrazine carboxy derivative (1), the dihalogenobutane (2) and the alkali metal carbonate or hydroxide may, for example, be within the range of 1:2-10:2-10, preferably, 1:2-5:2-5. The reaction temperature at that time may, for example, be from 10.degree. to 150.degree. C., preferably from 30.degree. C. to the reflux temperature. The reaction time may, for example, be from 2 to 48 hours, preferably form 5 to 24 hours.
Further, the hydrazine dicarboxy derivative (1) to be used as the starting material in h process of the present invention, can readily be prepared by the method disclosed in Organic Synthesis, col. vol. III, p. 375.
On the other hand, the hexahydropyrida
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patent: 4906281 (1990-03-01), Chang
Zinner et al, Chemical Abstracts, vol. 58, No. 4577 (1963).
Dervon et al, J. Am. Chem. Soc., vol. 102, pp. 3863-3870 (1980).
Bernhardt Emily
Ihara Chemical Industry Co. Ltd.
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